1. Field of the Invention
This invention relates to assembling electrical apparatus comprising a plurality of electrical wires. More specifically, this invention relates to the fabrication of an electrical harness comprising a single multi-contact electrical connector and a plurality of wires of different length. This invention also relates to simultaneous differential stripping of the insulation from the free ends of a plurality of wires.
2. Description of the Prior Art
Harness assemblies have long been fabricated by lacing wires along a prescribed pattern on a harness assembly board and subsequently applying electrical terminals to the ends thereof. This technique is largely manual and numerous attempts have been made to mechanize this operation. Although only illustrative, one such attempt to automate harness assembly is shown in U.S. Pat. No. 3,699,630.
With the advent of pre-loaded multi-contact electrical connectors which utilize slotted-plate insulation piercing wire termination techniques, modifications in the traditional harness fabrication techniques have been suggested. An example of one such modification is disclosed and claimed in U.S. Pat. No. 3,859,724. That method employed a harness assembly board with wire terminations being made to multi-contact connectors at various stations on the harness board.
The initial use of multi-contact slotted-plate electrical connectors was to interconnect multi-conductor electrical cables. Such cables are used extensively in the telephone industry. To terminate each of the wires in a telephone cable the outer sheath must be removed and the wires must be individually attached to the individual terminals. The connector disclosed in U.S. Pat. No. 3,760,335 is generally used with telephone cables. This connector can be sequentially attached to wires by the automatic apparatus disclosed in U.S. Pat. No. 3,766,622 or the wires can be mass terminated by using the device disclosed in U.S. Pat. No. 3,758,935.
Harness assemblies need not use pre-assembled sheathed cable similar to those used in the telephone industry. In order to simplify the harness assembly operation, wires may be drawn from reels and attached to the multi-contact connectors. If necessary, the wires can be subsequently bundled to form a cable. One such example of a method for fabricating a harness having similar multi-contact electrical connectors at both ends of the intervening wires is shown in application Ser. No. 657,138 filed Feb. 11, 1976. Application Ser. No. 679,961 filed April 26, 1976, also discloses an apparatus and method for fabricating a similar harness. This harness can not be utilized when different wires must be deployed to different physical locations, however. The harness fabricated by the method and apparatus disclosed and claimed herein is intended for use with conventional discrete electrical terminals or connectors attached to one end of a harness with the wires attached to a single multi-contact electrical connector at the opposite end.
U.S. Pat. No. 3,939,552 discloses a differential wire feed mechanism for feeding two wires of variable length. The wires are also stripped by conventional means.
U.S. Pat. No. 3,964,147 discloses a connector assembly machine which accepts wires with terminals attached and inserts the wires into a connector housing.
In general, conventional discrete electrical connectors and terminals are terminated to the ends of wires by either soldering or crimping. In either case, the insulation must be stripped from the ends of the individual wires prior to soldering and crimping. Two examples of wire stripping apparatus are disclosed in U.S. Pat. Nos. 3,309,948 and 3,815,449. If different types of wire terminations are to be made to separate wires it may be necessary to provide for different strip lengths on different wires. This differential stripping capability must be combined with wire feed and insertion apparatus which allows repetitive fabrication of substantially identical harnesses at a more rapid rate than more conventional harness fabrication techniques.